scholarly journals Blocks in Tricarboxylic Acid Cycle of Salmonella enterica Cause Global Perturbation of Carbon Storage, Motility, and Host-Pathogen Interaction

mSphere ◽  
2019 ◽  
Vol 4 (6) ◽  
Author(s):  
Janina Noster ◽  
Nicole Hansmeier ◽  
Marcus Persicke ◽  
Tzu-Chiao Chao ◽  
Rainer Kurre ◽  
...  
Keyword(s):  
Salmonella Enterica ◽  
Tricarboxylic Acid Cycle ◽  
Glycogen Synthesis ◽  
Tca Cycle ◽  
Carbon Fluxes ◽  
Tricarboxylic Acid ◽  
Cellular Functions ◽  
Content Type ◽  
Acid Cycle ◽  
Serovar Typhimurium

ABSTRACT The tricarboxylic acid (TCA) cycle is a central metabolic hub in most cells. Virulence functions of bacterial pathogens such as facultative intracellular Salmonella enterica serovar Typhimurium (S. Typhimurium) are closely connected to cellular metabolism. During systematic analyses of mutant strains with defects in the TCA cycle, a strain deficient in all fumarase isoforms (ΔfumABC) elicited a unique metabolic profile. Alongside fumarate, S. Typhimurium ΔfumABC accumulates intermediates of the glycolysis and pentose phosphate pathway. Analyses by metabolomics and proteomics revealed that fumarate accumulation redirects carbon fluxes toward glycogen synthesis due to high (p)ppGpp levels. In addition, we observed reduced abundance of CheY, leading to altered motility and increased phagocytosis of S. Typhimurium by macrophages. Deletion of glycogen synthase restored normal carbon fluxes and phagocytosis and partially restored levels of CheY. We propose that utilization of accumulated fumarate as carbon source induces a status similar to exponential- to stationary-growth-phase transition by switching from preferred carbon sources to fumarate, which increases (p)ppGpp levels and thereby glycogen synthesis. Thus, we observed a new form of interplay between metabolism of S. Typhimurium and cellular functions and virulence. IMPORTANCE We performed perturbation analyses of the tricarboxylic acid cycle of the gastrointestinal pathogen Salmonella enterica serovar Typhimurium. The defect of fumarase activity led to accumulation of fumarate but also resulted in a global alteration of carbon fluxes, leading to increased storage of glycogen. Gross alterations were observed in proteome and metabolome compositions of fumarase-deficient Salmonella. In turn, these changes were linked to aberrant motility patterns of the mutant strain and resulted in highly increased phagocytic uptake by macrophages. Our findings indicate that basic cellular functions and specific virulence functions in Salmonella critically depend on the proper function of the primary metabolism.

scholarly journals Blocks in tricarboxylic acid cycle of Salmonella enterica cause global perturbation of carbon storage, motility and host-pathogen-interaction

2019 ◽  
Author(s):  
Janina Noster ◽  
Nicole Hansmeier ◽  
Marcus Persicke ◽  
Tzu-Chiao Chao ◽  
Rainer Kurre ◽  
...  
Keyword(s):  
Salmonella Enterica ◽  
Tricarboxylic Acid Cycle ◽  
Glycogen Synthesis ◽  
Carbon Fluxes ◽  
Tricarboxylic Acid ◽  
Proper Function ◽  
Primary Metabolism ◽  
Cellular Functions ◽  
Acid Cycle ◽  
Serovar Typhimurium

AbstractThe tricarboxylic acid cycle is a central metabolic hub in most cells. Virulence functions of bacterial pathogens such as facultative intracellular Salmonella enterica serovar Typhimurium (STM) are closely connected to cellular metabolism. During systematic analyses of mutant strains with defects in TCA cycle, a strain deficient in all fumarase isoforms (ΔfumABC) elicited a unique metabolic profile. Alongside fumarate STM ΔfumABC accumulates intermediates of glycolysis and pentose phosphate pathway. Analyses by metabolomics and proteomics revealed that fumarate accumulation redirects carbon fluxes towards glycogen synthesis due to high (p)ppGpp levels. In addition, we observed reduced abundance of CheY, leading to altered motility and increased phagocytosis of STM by macrophages. Deletion of glycogen synthase restored normal carbon fluxes and phagocytosis, and partially levels of CheY. We propose that utilization of accumulated fumarate as carbon source induces a status similar to exponential to stationary growth phase transition by switching from preferred carbon sources to fumarate, which increases (p)ppGpp levels and thereby glycogen synthesis. Thus, we observed a new form of interplay between metabolism of STM, and cellular functions and virulence.ImportanceWe performed perturbation analyses of the tricarboxylic acid cycle of the gastrointestinal pathogen Salmonella enterica serovar Typhimurium. The defect of fumarase activity led to accumulation of fumarate, but also resulted in a global alteration of carbon fluxes, leading to increased storage of glycogen. Gross alterations were observed in proteome and metabolome compositions of fumarase-deficient Salmonella. In turn, these changes were linked to aberrant motility patterns of the mutant strain, and resulted in highly increased phagocytic uptake by macrophages. Our findings indicate that basic cellular functions and specific virulence functions in Salmonella critically depend on the proper function of the primary metabolism.

scholarly journals Role of Gluconeogenesis and the Tricarboxylic Acid Cycle in the Virulence of Salmonella enterica Serovar Typhimurium in BALB/c Mice

2006 ◽  
Vol 74 (2) ◽  
pp. 1130-1140 ◽  
Author(s):  
Merlin Tchawa Yimga ◽  
Mary P. Leatham ◽  
James H. Allen ◽  
David C. Laux ◽  
Tyrrell Conway ◽  
...  
Keyword(s):  
Salmonella Enterica ◽  
Tricarboxylic Acid Cycle ◽  
Carbon Sources ◽  
Tca Cycle ◽  
Tricarboxylic Acid ◽  
Glyoxylate Bypass ◽  
The Tca Cycle ◽  
Mouse Tissues ◽  
Serovar Typhimurium ◽  
Genes Encoding

ABSTRACT In Salmonella enterica serovar Typhimurium, the Cra protein (catabolite repressor/activator) regulates utilization of gluconeogenic carbon sources by activating transcription of genes in the gluconeogenic pathway, the glyoxylate bypass, the tricarboxylic acid (TCA) cycle, and electron transport and repressing genes encoding glycolytic enzymes. A serovar Typhimurium SR-11 Δcra mutant was recently reported to be avirulent in BALB/c mice via the peroral route, suggesting that gluconeogenesis may be required for virulence. In the present study, specific SR-11 genes in the gluconeogenic pathway were deleted (fbp, glpX, ppsA, and pckA), and the mutants were tested for virulence in BALB/c mice. The data show that SR-11 does not require gluconeogenesis to retain full virulence and suggest that as yet unidentified sugars are utilized by SR-11 for growth during infection of BALB/c mice. The data also suggest that the TCA cycle operates as a full cycle, i.e., a sucCD mutant, which prevents the conversion of succinyl coenzyme A to succinate, and an ΔsdhCDA mutant, which blocks the conversion of succinate to fumarate, were both attenuated, whereas both an SR-11 ΔaspA mutant and an SR-11 ΔfrdABC mutant, deficient in the ability to run the reductive branch of the TCA cycle, were fully virulent. Moreover, although it appears that SR-11 replenishes TCA cycle intermediates from substrates present in mouse tissues, fatty acid degradation and the glyoxylate bypass are not required, since an SR-11 ΔfadD mutant and an SR-11 ΔaceA mutant were both fully virulent.

scholarly journals A Dysfunctional Tricarboxylic Acid Cycle Enhances Fitness of Staphylococcus epidermidis During β-Lactam Stress

mBio ◽  
2013 ◽  
Vol 4 (4) ◽  
Author(s):  
Vinai Chittezham Thomas ◽  
Lauren C. Kinkead ◽  
Ashley Janssen ◽  
Carolyn R. Schaeffer ◽  
Keith M. Woods ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Citric Acid ◽  
Cell Surface ◽  
Staphylococcus Epidermidis ◽  
Citric Acid Cycle ◽  
Tricarboxylic Acid Cycle ◽  
Tca Cycle ◽  
Tricarboxylic Acid ◽  
Content Type ◽  
Acid Cycle

ABSTRACT A recent controversial hypothesis suggested that the bactericidal action of antibiotics is due to the generation of endogenous reactive oxygen species (ROS), a process requiring the citric acid cycle (tricarboxylic acid [TCA] cycle). To test this hypothesis, we assessed the ability of oxacillin to induce ROS production and cell death in Staphylococcus epidermidis strain 1457 and an isogenic citric acid cycle mutant. Our results confirm a contributory role for TCA-dependent ROS in enhancing susceptibility of S. epidermidis toward β-lactam antibiotics and also revealed a propensity for clinical isolates to accumulate TCA cycle dysfunctions presumably as a way to tolerate these antibiotics. The increased protection from β-lactam antibiotics could result from pleiotropic effects of a dysfunctional TCA cycle, including increased resistance to oxidative stress, reduced susceptibility to autolysis, and a more positively charged cell surface. IMPORTANCE Staphylococcus epidermidis, a normal inhabitant of the human skin microflora, is the most common cause of indwelling medical device infections. In the present study, we analyzed 126 clinical S. epidermidis isolates and discovered that tricarboxylic acid (TCA) cycle dysfunctions are relatively common in the clinical environment. We determined that a dysfunctional TCA cycle enables S. epidermidis to resist oxidative stress and alter its cell surface properties, making it less susceptible to β-lactam antibiotics.

scholarly journals Multiple Targets of Nitric Oxide in the Tricarboxylic Acid Cycle of Salmonella enterica Serovar Typhimurium

2011 ◽  
Vol 10 (1) ◽  
pp. 33-43 ◽  
Author(s):  
Anthony R. Richardson ◽  
Elizabeth C. Payne ◽  
Noah Younger ◽  
Joyce E. Karlinsey ◽  
Vinai C. Thomas ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Salmonella Enterica ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Tricarboxylic Acid Cycle ◽  
Tricarboxylic Acid ◽  
Multiple Targets ◽  
Acid Cycle ◽  
Serovar Typhimurium

scholarly journals HISTOCHEMICAL INVESTIGATIONS ON THE IN VIVO EFFECTS OF FLUORIDE ON TRICARBOXYLIC ACID CYCLE DEHYDROGENASES FROM PELARGONIUM ZONALE: PART II

1967 ◽  
Vol 15 (4) ◽  
pp. 202-206
Author(s):  
C. JAMES LOVELACE ◽  
GENE W. MILLER
Keyword(s):  
Sodium Fluoride ◽  
Reductase Activity ◽  
Tricarboxylic Acid Cycle ◽  
Leaf Tissue ◽  
Tca Cycle ◽  
Tricarboxylic Acid ◽  
Pelargonium Zonale ◽  
Acid Cycle ◽  
In Vivo Effects

In vivo effects of fluoride on tricarboxylic acid (TCA) cycle dehydrogenase enzymes of Pelargonium zonale were studied using p-nitro blue tetrazoleum chloride. Plants were exposed to 17 ppb HF, and enzyme activities in treated plants were compared to those in controls. Leaves of control plants were incubated in 5 x 10–3 M sodium fluoride. Injuries observed in fumigation and solution experiments were similar. Leaf tissue subjected to HF or sodium fluoride evidenced less succinic p-nitro blue tetrazoleum reductase activity than did control tissue. Other TCA cycle dehydrogenase enzymes were not observably affected by the fluoride concentrations used in these experiments. Excised leaves cultured in 5 x 10–3 M sodium fluoride exhibited less succinic p-nitro blue tetrazoleum reductase activity after 24 hr than did leaves cultured in 5 x 10–3 M sodium chloride.

scholarly journals Staphylococcus epidermidis Polysaccharide Intercellular Adhesin Production Significantly Increases during Tricarboxylic Acid Cycle Stress

2005 ◽  
Vol 187 (9) ◽  
pp. 2967-2973 ◽  
Author(s):  
Cuong Vuong ◽  
Joshua B. Kidder ◽  
Erik R. Jacobson ◽  
Michael Otto ◽  
Richard A. Proctor ◽  
...  
Keyword(s):  
Staphylococcus Epidermidis ◽  
Tricarboxylic Acid Cycle ◽  
Tca Cycle ◽  
Redox Status ◽  
Tricarboxylic Acid ◽  
Polysaccharide Intercellular Adhesin ◽  
Low Oxygen ◽  
Acid Cycle ◽  
The Tca Cycle ◽  
High Concentrations

ABSTRACT Staphylococcal polysaccharide intercellular adhesin (PIA) is important for the development of a mature biofilm. PIA production is increased during growth in a nutrient-replete or iron-limited medium and under conditions of low oxygen availability. Additionally, stress-inducing stimuli such as heat, ethanol, and high concentrations of salt increase the production of PIA. These same environmental conditions are known to repress tricarboxylic acid (TCA) cycle activity, leading us to hypothesize that altering TCA cycle activity would affect PIA production. Culturing Staphylococcus epidermidis with a low concentration of the TCA cycle inhibitor fluorocitrate dramatically increased PIA production without impairing glucose catabolism, the growth rate, or the growth yields. These data lead us to speculate that one mechanism by which staphylococci perceive external environmental change is through alterations in TCA cycle activity leading to changes in the intracellular levels of biosynthetic intermediates, ATP, or the redox status of the cell. These changes in the metabolic status of the bacteria result in the attenuation or augmentation of PIA production.

scholarly journals Metabolomics of Escherichia coli Treated with the Antimicrobial Carbon Monoxide-Releasing Molecule CORM-3 Reveals Tricarboxylic Acid Cycle as Major Target

2019 ◽  
Vol 63 (10) ◽  
Author(s):  
Sandra M. Carvalho ◽  
Joana Marques ◽  
Carlos C. Romão ◽  
Lígia M. Saraiva
Keyword(s):  
Escherichia Coli ◽  
Carbon Monoxide ◽  
Tricarboxylic Acid Cycle ◽  
Redox Homeostasis ◽  
Glutamate Synthase ◽  
Tca Cycle ◽  
Tricarboxylic Acid ◽  
Bacterial Cells ◽  
Content Type ◽  
Iron Sulfur

ABSTRACT In the last decade, carbon monoxide-releasing molecules (CORMs) have been shown to act against several pathogens and to be promising antimicrobials. However, the understanding of the mode of action and reactivity of these compounds on bacterial cells is still deficient. In this work, we used a metabolomics approach to probe the toxicity of the ruthenium(II) complex Ru(CO)3Cl(glycinate) (CORM-3) on Escherichia coli. By resorting to 1H nuclear magnetic resonance, mass spectrometry, and enzymatic activities, we show that CORM-3-treated E. coli accumulates larger amounts of glycolytic intermediates, independently of the oxygen growth conditions. The work provides several evidences that CORM-3 inhibits glutamate synthesis and the iron-sulfur enzymes of the tricarboxylic acid (TCA) cycle and that the glycolysis pathway is triggered in order to establish an energy and redox homeostasis balance. Accordingly, supplementation of the growth medium with fumarate, α-ketoglutarate, glutamate, and amino acids cancels the toxicity of CORM-3. Importantly, inhibition of the iron-sulfur enzymes glutamate synthase, aconitase, and fumarase is only observed for compounds that liberate carbon monoxide. Altogether, this work reveals that the antimicrobial action of CORM-3 results from intracellular glutamate deficiency and inhibition of nitrogen and TCA cycles.

THE DIRECT ACTION OF CCl4ON THE METABOLISM OF LIVER SLICES

1965 ◽  
Vol 43 (6) ◽  
pp. 647-659 ◽  
Author(s):  
Peter R. Weldon ◽  
Bernard Rubenstein ◽  
David Rubinstein
Keyword(s):  
Amylase Activity ◽  
Direct Action ◽  
Tricarboxylic Acid Cycle ◽  
Glycogen Synthesis ◽  
Hepatic Metabolism ◽  
Tricarboxylic Acid ◽  
Acid Cycle ◽  
Liver Slices ◽  
Low Concentrations

The metabolism of glucose, galactose, leucine, acetate, and palmitate by rat liver slices incubated in the presence of varying amounts of CCl4was studied. Carbon tetrachloride, 1 to 9 μl, introduced into the side arm of a Warburg vessel, produced concentrations in the slices of 0.4 to 3.3 mg/g liver. At these concentrations the CCl4produced a decrease in C14O2production from succinate-2,3-C14and glucose-6-C14, but not from glucose-1-C14. The presence of CCl4did not appreciably affect CO2production from glucose-U-C14or galactose-1-C14but stimulated the incorporation of the monosaccharides into glycogen at the lower concentrations (1 mg CCl4/g liver). Higher concentrations of CCl4(2 mg/g liver) inhibited glycogen synthesis; the activities of glycogen synthetase and phosphorylase were decreased, but amylase activity and the level of glucose-6-phosphate in the liver slices remained unchanged. The oxidation of palmitate-1-C14and acetate-1-C14to C14O2is decreased at the higher concentrations of CCl4, while lipogenesis from acetate is stimulated by lower concentrations of CCl4. Esterification of palmitate is not affected by the presence of CCl4. It is concluded that the function of the tricarboxylic acid cycle is altered by CCl4and that acetate may be shunted into fatty acids. The oxidation of leucine-1-C14and the incorporation of the amino acid into protein were diminished in the presence of low concentrations of CCl4. These findings and the changes observed after CCl4administration in vivo are compared, and support is found for the view that CCl4affects hepatic metabolism in vivo directly.

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